Rules for Line of Sight
I am a fan of loop puzzles. When I saw this one, I thought "that's clever". The names it was under were Sight and Site Line, but I thought Line of Sight had a better ring to it. For the Layout I had several ideas which you can see here. The right top one was preferred by people I asked. The left top one is the original layout. If people prefer it differently, I don't mind drawing them differently.
As for the puzzle, it's not too hard. I figured I'd introduce this genre a bit more gently than I normally do. I have this tendency to make really hard first puzzles as it helps me discover what you can do with a genre.
[Edit] First puzzle was not unique. Fixed the left bottom corner.